Method of forging six-throw crank shafts and dies therefor



Web 11, 1924; 1,486,583

H. H. KEEPORTS METHOD OF FORGIN G SIX-THROW CRANK SHAFTS AND DIES THEREFOR Filed Oct. 15. 1922 5 Sheets-Sheet 1 INVENTOR. Harry M. Keepawi's M ma ATTORNEYS Marsh 11, I924 1,486,588

H. H. KEEPORTS METHOD OF FORGING SYIX-THROW CRANK SHAFTS AND DIES THEREFOR Filed 001. 15 1922 E 5 Sheets-Sheet 2 w I l INVENTJR.

Harry H. Keeports ATTORNEYE 'MMQh 11, 1924;

H. H. KEEPORTS METHOD OF FORGING SIX-THROW CRANK SHAFTS AND DIES THEREFOR Filed Oct. 13. 1922 5 Sheets-Sheet 5 INVENTOR fiflrry H. Keeporfs Q & WW ATTORNEYfi March 11, 1924-;

H. H. KEEPQRTS METHOD OF FORGING SIX-THROW CRANK SHAFTS AND DIES THEREFOR Filed 001:. 13. 1922 5 Sheets-Sheet 4 INVENTOR. Harry h. flee aorta following specification.

Patented Mar. II, 1924. 4

I F F I IE an n. nnnroa'rs, or camera, 018110.

Appfieation filed October 13, 1922. Serial Ito. 594,278.

To all whom it may concern;

Be it known that I, HARRY H. Knnronrs,

a citizen of the United States, residing at Canton, county of Stark, State of Ohio,

have invented certain new and useful Imrovements in Methods of Forging Sixhrow Crank Shafts and Dies Therefor,

of which the following is aspecification.

This invention relates to an improved method of forging six-throw crank-shafts for automobile engines or similar purpose and the dies therefor.

The object of the invention is to improve such method of forging and avoid undue stretching and straining of the metal and minimize torsional strains of the forging operation.

Objects pertaining to details and economies of construction and operation will definitely appear from the detailed description to follow.

I accomplish the objects of my invention by the devices and means described in the The invention is clearly defined and pointed out in the claims.

A structure which is a preferred embodiment of my invention is clearly illustrated in the accompan ing drawing forming a part of this speci cation, in which:

Fi I isa side elevation view of a bar that as been submitted to the first step in an edger die in my forgin operation.

II is a plan view 0 the structure of Fig. III is an elevation view of the bar after it has been submitted to the second edger die forging operation.

Fig. IV is a plan view of the structure of Fig. III.

Fig. V is a plan view of the completed shaft after the final die operation.

Fig. VI is an elevation view of the completed shaft.

Fig. VII is a cross sectional view taken on line 7-7 of Fig. V..

Fig. VIII is a detail sectional view taken on irre lar line 8-'8 of Fig. V.

i is a detail sectional view takenon irre lar line 99 of Fig. VI.

Fig. is a detail sectional view taken on line 10-10 of Fig. V.

Fi. XI is an inverted plan view of the top w member with the corresponding depressions therein.

Fig. is a detail plan view of the bottom die showing the three successive sets of die depressions therein.

Fig. XIII is a detail longitudinal sectional view through the superposed die depressions in the first edger, showing the billet in position in the first step of my process.

Fig. XIV is a similar longitudinal sectional viewthrough the second-edger depressions showing the action or the dies in the second step of my process.

In the drawing the sectional views are.

taken looking in the direction of the little arrows at the ends of the section lines and similar numerals of reference refer to similar parts throughout the several views.

The various parts of the drawing will be identified by their reference numerals. 1 is'the billet bar to be handled by its shank 2. Itis placed firstin the first edger die and the central art deflected up as at 3 (see Fig. I) whic results in the bar being somewhat flattened at that point, as shown in Fig. II. In the second step the deflected part 3 is turned to horizontal position; that is, the bar is turned one quarter over, and the second edger die is brought into action, forming roughly double throws 4 and 5. and 6 and 7 at each end of the bar, as clearly appears in side elevation in Fig. III. The metal is flattened-down to the general contour of the plan appearing in Fig. IV.

The" bar is then subjected to the third operation between the complete forming dies, the upwardly deflected portion being placed on the upwardly projecting central portion of the die and the end portions eing forced down b a forging and slight bending action unti the crank pins are formed in op osite relation, as seen in plan in Fig. V an in elevation in Fig. VI.

There is a single crank arm 8 and 9 at opposite ends, and single central crank arms 10 and 11, and 12 and 13 at each side of the intermediate crank hearing. There are double crank throw arms 14 and 15 connecting the first and second crank pins and the fifth and sixth crank pins at each end, the same having deflected and curved forms,

- as seen in cross section in Fig. VII.

After the final forming of the crank, oi

\ course, the fins should be removedb suitable cutter dies, which is a mere inci ent of all such operations. The flange head 16 is formed in the usual way and I have not described it in detail.

Iii

till

the top die. I form an edger depression 19 at one edge, which appeamm long1tud1- nal section in Fig XIII. A second edger die 20 is formed where the billet is turned a quarter over. The general contour. of'

the part appears in elevation in XIV. There is a final depression die 1n wh1ch the complete contour of the six throw crank shaft is formed. The central cranks are in a vertical central lane and the end cranks are deflected laterally 120 therefrom at each side, as definitely appears on the faoe of said upper and lower dies illustrated in XI and XII. The three die-impressions can be in separate blocks or combined in blocks to suit individual manufacturing conditions, and can be used as described or reversed.

It will be seen from these steps that the end cranks are deflected downwardly and the double throw cranks 14 and 15 are only slightly bent, as indicated in Fig. VIII, to accomplish the complete formatlon of the six throw crank shaft. The metal is only stretched to the extent that it would ordinarily be stretched in forming a single crank, and the torsion is substantially negligible,

although the crank shaft is being acted upon from end to end by the final dies at the same moment.

The deflecting of the center of the billet could be done as the second operation with the formation of the end crank throws as the first, but the operation would be far less convenient and satisfactory, as it is much easier to handle the straight bar while the center is being deflected than to properly manipulate and place it with the end cranks formed in the rough. I mention this as a possible change in procedure, without de-,

parting from the broad principles -of the working relation between the steps of manufacture of my invention. However, I desire to claim the invention in its approved form specifically as I have descri broadly, as pointed out in the appended claims.

Having thus described by invention what I claimasnew and desire to secure by Letters Patent is:

1. The rocess of forming a six throw crank sha consisting in, first, deflecting to one side the central portion for the central air of crank pins and-arms, second, form'- mg the first and second and the fifth and sixth crank pins and arms ateach end at right angles thereto, with a connecting crank between the first and second and the fifth and sixth pins, and third, subjecting the sameto a forging action in which the central crank pins are roughly completed and the end two crank pins and arms are deflected from theright angle lane to an angle of 120 degrees and completely rough formed, as specified.

2. The process of forming a six throw crank shaft consisting in deflecting the central part to form the central pair of crank pins and arms, and forming the first and second and fifth and sixth crank pins and arms at right angles thereto, and thereafter subjecting the same to a forgin operation in dies conformed to the form 0 the crank whereby the end crank pins and arms are deflected to position.

3. A- series of dies for forming a crank shaft, one of which is formed with a central depression to deflect the center crank throws, another of which is conformed to produce crank throws at the ends of the shaft at right angles to the first deflected portion, and a final forming die with a vertical central portion to conform the central crank throw and deflected lateral portions to form the end crank throws, as specified.

In witness whereof, I have hereunto set my hand and seal.

HARRY H. KEEPORTS. [L 8.]

bed, and also 

